<?php
class wechatAppPay
{ 
//接口API URL前缀
const API_URL_PREFIX = 'https://api.mch.weixin.qq.com';
//下单地址URL
const UNIFIEDORDER_URL = "/pay/unifiedorder";
//查询订单URL
const ORDERQUERY_URL = "/pay/orderquery";
//关闭订单URL
const CLOSEORDER_URL = "/pay/closeorder";
//公众账号ID
private $appid;
private $openid;
//商户号
private $mch_id;
//随机字符串
private $nonce_str;
//签名
private $sign;
//商品描述
private $body;
//商户订单号
private $out_trade_no;
//支付总金额
private $total_fee;
//终端IP
private $spbill_create_ip;
//支付结果回调通知地址
private $notify_url;
//交易类型
private $trade_type;
//支付密钥
private $key;
//证书路径
private $SSLCERT_PATH;
private $SSLKEY_PATH;
//所有参数
private $params = array();
public function __construct($appid, $mch_id, $notify_url, $key)
{
$this->appid = $appid;
$this->mch_id = $mch_id;
$this->notify_url = $notify_url;
$this->key = $key;
}

/**
* 下单方法
* @param $params 下单参数
*/
public function unifiedOrder( $params ){
//$this->key =$params['key'];
$this->openid= $params['openid'];
$this->body = $params['body'];
$this->out_trade_no = $params['out_trade_no'];
$this->total_fee = $params['total_fee'];
$this->trade_type = $params['trade_type'];
$this->nonce_str = $params['nonce_str'];//$this->genRandomString();//
$this->spbill_create_ip = $_SERVER['REMOTE_ADDR'];
$this->params['appid'] = $this->appid;
$this->params['mch_id'] = $this->mch_id;
$this->params['nonce_str'] = $this->nonce_str;
$this->params['body'] = $this->body;
$this->params['out_trade_no'] = $this->out_trade_no;
$this->params['total_fee'] = $this->total_fee;
$this->params['spbill_create_ip'] = $this->spbill_create_ip;
$this->params['notify_url'] = $this->notify_url;
$this->params['trade_type'] = $this->trade_type;
$this->params['openid'] = $this->openid;
//获取签名数据
$this->sign = $this->MakeSign( $this->params );
$this->params['sign'] = $this->sign;
$xml = $this->data_to_xml($this->params);
$response = $this->postXmlCurl($xml, self::API_URL_PREFIX.self::UNIFIEDORDER_URL);
if( !$response ){
return false;
}
$result = $this->xml_to_data( $response );
if(!empty($result['result_code']) && !empty($result['err_code']) ){
$result['err_msg'] = $this->error_code( $result['err_code'] );
}
return $result;
}
/**
* 查询订单信息
* @param $out_trade_no 订单号
* @return array
*/
public function orderQuery( $out_trade_no ){
$this->params['appid'] = $this->appid;
$this->params['mch_id'] = $this->mch_id;
$this->params['nonce_str'] = $this->genRandomString();
$this->params['out_trade_no'] = $out_trade_no;
//获取签名数据
$this->sign = $this->MakeSign( $this->params );
$this->params['sign'] = $this->sign;
$xml = $this->data_to_xml($this->params);
$response = $this->postXmlCurl($xml, self::API_URL_PREFIX.self::ORDERQUERY_URL);
if( !$response ){
return false;
}
$result = $this->xml_to_data( $response );
if( !empty($result['result_code']) && !empty($result['err_code']) ){
$result['err_msg'] = $this->error_code( $result['err_code'] );
}
return $result;
}
/**
* 关闭订单
* @param $out_trade_no 订单号
* @return array
*/
public function closeOrder( $out_trade_no ){
$this->params['appid'] = $this->appid;
$this->params['mch_id'] = $this->mch_id;
$this->params['nonce_str'] = $this->genRandomString();
$this->params['out_trade_no'] = $out_trade_no;
//获取签名数据
$this->sign = $this->MakeSign( $this->params );
$this->params['sign'] = $this->sign;
$xml = $this->data_to_xml($this->params);
$response = $this->postXmlCurl($xml, self::API_URL_PREFIX.self::CLOSEORDER_URL);
if( !$response ){
return false;
}
$result = $this->xml_to_data( $response );
return $result;
}
/**
* 
* 获取支付结果通知数据
* return array
*/
public function getNotifyData(){
//获取通知的数据
$xml = $GLOBALS['HTTP_RAW_POST_DATA'];
$data = array();
if( empty($xml) ){
return false;
}
$data = $this->xml_to_data( $xml );
if( !empty($data['return_code']) ){
if( $data['return_code'] == 'FAIL' ){
return false;
}
}
return $data;
}
/**
* 接收通知成功后应答输出XML数据
* @param string $xml
*/
public function replyNotify(){
$data['return_code'] = 'SUCCESS';
$data['return_msg'] = 'OK';
$xml = $this->data_to_xml( $data );
echo $xml;
die();
}
/**
* 生成APP端支付参数
* @param $prepayid 预支付id
*/
public function getAppPayParams( $prepayid ){
$data['appid'] = $this->appid;
$data['partnerid'] = $this->mch_id;
$data['prepayid'] = $prepayid;
$data['package'] = 'Sign=WXPay';
$data['noncestr'] = $this->genRandomString();
$data['timestamp'] = time();
$data['sign'] = $this->MakeSign( $data ); 
return $data;
}
/**
* 生成签名
* @return 签名
*/
public function MakeSign( $params ){
//签名步骤一：按字典序排序数组参数
ksort($params);
$string = $this->ToUrlParams($params);
//签名步骤二：在string后加入KEY

$string = $string . "&key=".$this->key;

//签名步骤三：MD5加密
$string = md5($string);
//签名步骤四：所有字符转为大写
$result = strtoupper($string);
return $result;
}
/**
* 将参数拼接为url: key=value&key=value
* @param $params
* @return string
*/
public function ToUrlParams( $params ){
$string = '';
if( !empty($params) ){
$array = array();
foreach( $params as $key => $value ){
$array[] = $key.'='.$value;
}
$string = implode("&",$array);
}
return $string;
}
/**
* 输出xml字符
* @param $params 参数名称
* return string 返回组装的xml
**/
public function data_to_xml( $params ){
if(!is_array($params)|| count($params) <= 0)
{
return false;
}
$xml = "<xml>";
foreach ($params as $key=>$val)
{
if (is_numeric($val)){
$xml.="<".$key.">".$val."</".$key.">";
}else{
$xml.="<".$key."><![CDATA[".$val."]]></".$key.">";
}
}
$xml.="</xml>";
return $xml; 
}
/**
* 将xml转为array
* @param string $xml
* return array
*/
public function xml_to_data($xml){ 
if(!$xml){
return false;
}
//将XML转为array
//禁止引用外部xml实体
libxml_disable_entity_loader(true);
$data = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true); 
return $data;
}
/**
* 获取毫秒级别的时间戳
*/
private static function getMillisecond(){
//获取毫秒的时间戳
$time = explode ( " ", microtime () );
$time = $time[1] . ($time[0] * 1000);
$time2 = explode( ".", $time );
$time = $time2[0];
return $time;
}
/**
* 产生一个指定长度的随机字符串,并返回给用户 
* @param type $len 产生字符串的长度
* @return string 随机字符串
*/
private function genRandomString($len = 32) {
$chars = array(
"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k",
"l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v",
"w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G",
"H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R",
"S", "T", "U", "V", "W", "X", "Y", "Z", "0", "1", "2",
"3", "4", "5", "6", "7", "8", "9"
);
$charsLen = count($chars) - 1;
// 将数组打乱 
shuffle($chars);
$output = "";
for ($i = 0; $i < $len; $i++) {
$output .= $chars[mt_rand(0, $charsLen)];
}
return $output;
}
/**
* 以post方式提交xml到对应的接口url
* 
* @param string $xml 需要post的xml数据
* @param string $url url
* @param bool $useCert 是否需要证书，默认不需要
* @param int $second url执行超时时间，默认30s
* @throws WxPayException
*/
private function postXmlCurl($xml, $url, $useCert = false, $second = 30){ 
$ch = curl_init();
//设置超时
curl_setopt($ch, CURLOPT_TIMEOUT, $second);
curl_setopt($ch,CURLOPT_URL, $url);
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,FALSE);
curl_setopt($ch,CURLOPT_SSL_VERIFYHOST,2);
//设置header
curl_setopt($ch, CURLOPT_HEADER, FALSE);
//要求结果为字符串且输出到屏幕上
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
if($useCert == true){
//设置证书
//使用证书：cert 与 key 分别属于两个.pem文件
curl_setopt($ch,CURLOPT_SSLCERTTYPE,'PEM');
//curl_setopt($ch,CURLOPT_SSLCERT, WxPayConfig::SSLCERT_PATH);
curl_setopt($ch,CURLOPT_SSLKEYTYPE,'PEM');
//curl_setopt($ch,CURLOPT_SSLKEY, WxPayConfig::SSLKEY_PATH);
}
//post提交方式
curl_setopt($ch, CURLOPT_POST, TRUE);
curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
//运行curl
$data = curl_exec($ch);
//返回结果
if($data){
curl_close($ch);
return $data;
} else { 
$error = curl_errno($ch);
curl_close($ch);
return false;
}
}
/**
* 错误代码
* @param $code 服务器输出的错误代码
* return string
*/
public function error_code( $code ){
$errList = array(
'NOAUTH' => '商户未开通此接口权限',
'NOTENOUGH' => '用户帐号余额不足',
'ORDERNOTEXIST' => '订单号不存在',
'ORDERPAID' => '商户订单已支付，无需重复操作',
'ORDERCLOSED' => '当前订单已关闭，无法支付',
'SYSTEMERROR' => '系统错误!系统超时',
'APPID_NOT_EXIST' => '参数中缺少APPID',
'MCHID_NOT_EXIST' => '参数中缺少MCHID',
'APPID_MCHID_NOT_MATCH' => 'appid和mch_id不匹配',
'LACK_PARAMS' => '缺少必要的请求参数',
'OUT_TRADE_NO_USED' => '同一笔交易不能多次提交',
'SIGNERROR' => '参数签名结果不正确',
'XML_FORMAT_ERROR' => 'XML格式错误',
'REQUIRE_POST_METHOD' => '未使用post传递参数 ',
'POST_DATA_EMPTY' => 'post数据不能为空',
'NOT_UTF8' => '未使用指定编码格式',
); 
if( array_key_exists( $code , $errList ) ){
return $errList[$code];
}
}
}

?>